Subject: [mobile-ip] Mobile IPv6 Issue 73 (MaxRtrAdvtInterval)

From: [email-masked]
Date: Wed, 18 Sep 2002 17:23:51 -0500

Issue 73: MaxRtrAdvInterval
---------------------------

http://www.piuha.net/~jarkko/publications/mipv6/issues/issue73.txt

In Section 7.5, this number is defined to be 1.5 seconds, but there
may be certain wireless links where periodic multicast router
advertisements are unnecessary or expensive for reasons of spectral
efficiency. 

Proposal: The network administrator should have the option of
configuring this off in such cases. 

Recommendation:
---------------

The primary mechanism for movement detection in Mobile IP is via
listening to router advertisements. Hence in order to support seamless
mobility it is important that the advertisement interval be
sufficiently low in order to enable MNs to detect link
changes. However it is possible that in certain networks movement
detection may be accomplished via other means (link layer) and hence
the need for rtr advts is mitigated. And there may be no reason to
send unsolicited multicase router advertisements periodically at all. 

The following text should be added to the current section 7.5 which
would allow network operators to turn off unsolicited multicast rtr
advts.

"
Multicast router advertisements are not always required in certain
wireless networks that have limited bandwidth. Mobility detection or
link changes in such networks may be done at lower layers. Router
advertisements in such networks SHOULD be sent only when solicited. In
such networks it SHOULD be possible to disable unsolicited multicast
router advertisements on specific interfaces. The MaxRtrAdvInterval in
such a case can be set to some high value such as 31536000.
"

If you have any concerns with the above recommendation, please send a
note to the Mobile IP mailing list.

-Basavaraj

---

From: Jari Arkko <[email-masked]>
Date: Thu, 19 Sep 2002 09:53:54 +0300

> such a case can be set to some high value such as 31536000.

I agree, but I would delete "such as 31536000". (How did you arrive
at this particular number, by the way?)

Jari

---

From: Behcet Sarikaya <[email-masked]>
Date: Thu, 19 Sep 2002 09:59:18 -0500

I have two reactions:
  This is MIPv4 coming back to MIPv6, once someone had suggested 
removing RO from MIPv6 spec, so this proposal is in line with his proposal?
  One conclusion is we are talking about only WLANs links to which every 
new feature in MIPv6 is applicable?
  Keep up the good and hard work.
Regards,

-- 
Behcet